CN1321839A

CN1321839A - Forced draught blower

Info

Publication number: CN1321839A
Application number: CN01117258A
Authority: CN
Inventors: 藤中广康
Original assignee: Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Holdings Corp
Priority date: 2000-04-27
Filing date: 2001-04-27
Publication date: 2001-11-14
Anticipated expiration: 2021-04-27
Also published as: JP4441978B2; US6602051B2; US20010041136A1; CN1232735C; JP2001304196A

Abstract

The present invention provides a blowing apparatus with improved energy efficiency, comprising: a circular wall formed at a distance from a blade end of a fan; a first region where an inner diameter is enlarged so that a clearance with the blade end becomes substantially wide, and a second region having a narrower clearance with the blade end and formed with a slit, both regions being on a suction side of the circular wall; and an air pocket portion provided between an outer circumference of the circular wall and an outer peripheral portion of the housing.

Description

Blast device

The present invention relates to blast device.

In recent years, because miniaturization, the electronization of equipment, the high-density installation of electric wiring widely adopts.Because the heat generation density of corresponding electronic device increases therewith, blast device is used to apparatus cools.

In addition, because the cost degradation of equipment, even the blast device that is used for these equipment has also been proposed the strong request of cost degradation.

As shown in figure 12, existing blast device is that the blade front end with fan 1 is separated with at interval and forms annular wall 2, and under the ventilation state of motor part 3 energisings, axial fan 1 be the center rotation with axle 4 and produces from attracting the air stream 5 of side towards the discharge side.

Yet, under above-mentioned ventilation state, the speeding up of the back pressure side air stream of blade front end, this tie up to be transformed to pressure can the trailing edge side produce the low energy area that the influence of secondary flow between blade causes.Mobile peeling off taken place greatly and easily and air stream and blade face broken away from this partial loss, and produces eddy current in its disengaging zone, thereby makes the turbulence noise increase, causes the problem of noise level and air volume-static pressure characteristic degradation.

Especially the occasion that occurs flow impedance (system impedance) in the discharge currents side, the leakage eddy current that the blade front end produces increases, and fan sinks into to be the situation of stall conditions, and this phenomenon is of common occurrence.

In view of this, the object of the present invention is to provide a kind ofly when performance surpasses existing blast device, productivity and cost-performance all are better than the blast device of existing blast device.

The blade front end of blast device system of the present invention and fan is separated with at interval and forms annular wall, above-mentioned annular wall is by making the local first area that enlarges of internal diameter and constituting with second area that the preceding splaying of blade dwindles, thereby make and attract the gap of the blade front end of side to increase in fact, the terminal of second area is an interrupt status discharging side, and by between annular wall periphery and housing outer peripheral portion, forming the characteristic that has certain volume and improve blast device to the air bag portion that the discharge side is opened.

Adopt the present invention can improve the characteristic of blast device,, the cost-performance of blast device is improved simultaneously by the realization cost degradation of boosting productivity.

Technological scheme 1 of the present invention is a kind of blast device, be separated with at interval and the housing that forms annular wall and have the hub portion of integrally formed above-mentioned annular wall and fixed motor with the blade front end of fan, it is characterized in that, the terminal of above-mentioned annular wall is an interrupt status discharging side, is formed with the air bag portion that has certain volume and open to the discharge side between annular wall periphery and housing outer peripheral portion.Can in the noise that reduces blast device, reduce production costs.

In addition, a kind of blast device is characterized in that, annular wall is by making the local first area that enlarges of internal diameter and constituting with second area that the preceding splaying of blade dwindles, thereby make and attract the gap of the blade front end of side to increase in fact, can improve the air-supply characteristic of blast device.

In addition, a kind of blast device is characterized in that, the hub portion of above-mentioned housing combines with annular wall portion, is not directly installed in housing peripheral part and the mounting hole portion.Can be reduced in the noise and the vibration of equipment under the state of equipment that blast device is installed on.

Technological scheme 2 of the present invention is a kind of blast device, it is characterized in that, as total quality with m (kilogram) expression motor and fan, with the spring constant between k (Newton/meter) expression hub portion and the assembly department, with the rotating speed of N (1/ second) expression motor, then housing is set for and is satisfied following relation:

N > 2 π \sqrt{\frac{k}{m}}

For reaching the invention effect of technological scheme 1, this combination beyond doubt effectively.

Technological scheme 3 of the present invention is a kind of blast device, be separated with at interval and the formation annular wall with the blade front end of fan, and housing with hub portion of integrally formed above-mentioned annular wall and fixed motor, it is characterized in that, above-mentioned annular wall 2 is by making the local first area that enlarges of internal diameter and constituting with second area that the preceding splaying of blade dwindles, thereby make and attract the gap of the blade front end of side to increase in fact, the terminal of second area is an interrupt status discharging side, has certain volume and when discharging the air bag portion that side opens being formed with between annular wall periphery and the housing outer peripheral portion, on above-mentioned annular wall, be formed with week and the groove that can make the air flows of air bag portion in the annular wall, have the effect of improving the air-supply characteristic under the higher state of static pressure.

In addition, because the housing of blast device only adopts the die forming that is made of core up and down, so can realize productivity raising and cost degradation.

The accompanying drawing simple declaration:

Figure 1A, 1B, 1C and 1D are respectively profile, front elevation, sectional drawing and the X-X1 sectional drawing of the blast device of embodiments of the invention 1.

Fig. 2 represents the explanatory drawing of the air flows of blast device in the past.

Fig. 3 is the explanatory drawing of the air flows of the blast device of the expression embodiment of the invention.

Fig. 4 represents the figure of the mould structure of the housing molding of blast device in the past.

Fig. 5 is the figure of the mould structure of the housing molding of the blast device of the expression embodiment of the invention.

Fig. 6 A, 6B, 6C and 6D are respectively profile, front elevation, sectional drawing and the X-X1 sectional drawing of the blast device of embodiments of the invention 2.

Fig. 7 A, 7B, 7C are respectively front elevation, profile and the plan view of the mounting fixture of blast device.

Fig. 8 A and 8B are respectively simple declaration figure and the frequency of expression vibration and the explanatory drawing of relationship of amplitude of vibration system.

Fig. 9 A, 9B, 9C and 9D are respectively profile, front elevation, sectional drawing and the X-X1 sectional drawing of the blast device of embodiments of the invention 3.

Figure 10 is the explanatory drawing of the air flows of the blast device of the expression embodiment of the invention.

Figure 11 is the characteristic of the blast device of the embodiment of the invention and the figure that in the past compared.

Figure 12 is the sectional drawing of blast device in the past.

Followingly embodiments of the invention are described according to Fig. 1-Fig. 7.

(embodiment 1)

Figure 1A to 1D represents embodiment 1 blast device.Wherein, Figure 1A is the profile of blast device, and Figure 1B is a front elevation, and Fig. 1 C is a sectional drawing, and Fig. 1 D is the X-X1 sectional drawing.

Shown in Fig. 1 D, annular wall 2 increases thereby make with the gap of the blade front end that attracts side is substantive by making the local first area that enlarges of internal diameter and constituting with second area that the preceding splaying of blade dwindles, and the terminal of second area is an interrupt status discharging side.In addition, between annular wall periphery and housing peripheral part 10, form air bag portion 11 with certain volume.

The principle of this blast device now is described by Fig. 2, Fig. 3.

Fig. 2 is illustrated in in the past the blast device, and being shaped as of suction oral-lateral of annular wall enlarged internal diameter to increase the occasion with the gap of blade front end.

Adopt this structure, producing by attracting side in the air stream 5 of discharging side by making fan 1 turn round to drive along the direction of gyratory directions 9, and from blade fore-end suction air stream 5, compare with the occasion that the gap is certain, particularly have the effect that air quantity is increased.

This part increases because of the gap with the blade front end, and the influence of air viscosity reduces, and the fashionable energy loss of air stream reduces, so can increase air quantity effectively.

Though setting makes the internal diameter enlarged can increase air quantity when low pressure, but as when under applying to a certain degree pressure state, using then as shown in Figure 2, leakage eddy current 7 at blade front end place from the malleation effluent to the back pressure side increases greatly, air stream and blade face break away from, and at the turbulent eddy current 8 of this disengaging zone generation, thereby make turbulence noise increase noise level and air volume-static pressure characteristic degradation.

It is not too big in the attraction side increase of blade front end that this blade front end leaks eddy current 7, increases greatly below the intermediate portion of blade front end on the contrary, has a significant impact for the performance of fan.

Fig. 3 is the explanatory drawing of the air flows of expression present embodiment 1.

As shown in Figure 3, in the present embodiment 1 by between this annular wall 2 and housing peripheral part 10, air bag portion 11 being set, the blade front end that increases greatly below the intermediate portion of blade front end leaks eddy current 7 discharges side in case attracted by this air bag portion 11 at fan 1, promptly since the turbulent eddy current 8 that produces here decay in the air bag degree and discharge to discharging side, so can in the reduction noise, improve air volume-static pressure characteristic (especially noise level).

In addition, the housing of the housing of this blast device and in the past blast device mutually specific energy increase substantially productivity.

Its reason can be utilized Fig. 4, Fig. 5 explanation.

Fig. 4 for expression to the skeleton diagram of the structure of the mould of the housing molding of blast device in the past.

Usually, carrying out with resin or metal is the occasion of the injection molding forming (or similar mould-forming method such as die cast metal, thixo casting) etc. of material, when making the thickness of each several part make extreme variation, produce so-called shrinkage cavity because of material contracts makes shape become flat, thereby precision is difficult to keep.

Therefore, in the occasion that the sort of shape of housing of blast device is in the past formed, be to make whole thickness recess is set for roughly definitely the shape of housing being formed in periphery, as shown in Figure 4, normally by

core

12,13 up and down and along and their Vertical direction over against and the mould structure that is shaped of 2 slide cores 14,15 of sliding.

The structure of the mould that Fig. 5 forms the housing of the blast device of present embodiment 1 for expression.

Among Fig. 5, the housing of present embodiment 1 system is by there not being simple 2 12 up and down, 13 of slide core to cooperate the mould that constitutes to be shaped.

Because housing is the shape of present embodiment 1, become the part of air suction inlet, be used to install the mounting hole 18 of blast device, the hub portion 16 of fixed motor portion, the disc portion 17 of support cage portion 16, can improve the air bag portion 11 of fan duty etc., can form than much simple mould in the past by structure, because the minimizing of Mold Making expense or the miniaturization of mould, compared with the past have and can form with the equipment of miniaturization, can boost productivity and cost degradation in by simplifying mould structure and reducing moving element, can obtain in the stable prod precision mould and safeguard effect such as become easily.

In addition, the housing of present embodiment is owing to be provided with air bag portion 11, and it is roughly certain that whole thickness keeps, so shrinkage cavity that can be when control is shaped, improve the material of saving nonuseable part in the precision, can realize lightweight, the minimizing cost of material.

(embodiment 2)

Fig. 6 A to 6D represents the housing of embodiment 2 blast device.Wherein, Fig. 6 A is a profile, and Fig. 6 B is a front elevation, and Fig. 6 C is a sectional drawing, and Fig. 6 D is the X-X1 sectional drawing.

In Fig. 6 A to 6D, embodiment 2 housing is characterised in that, the spoke 17 that the hub portion 16 that is fixed with motor is supported is fixed with annular wall portion, and directly be not fixed in housing peripheral part 10 or the motor mounting hole portion 18.The shape of other parts is then identical with embodiment 1 housing.Fig. 7 A to 7C represents mounting fixture.Wherein, Fig. 7 A is a front elevation, and Fig. 7 B is a profile, and Fig. 7 C is a plan view.

Can adopt mounting hole 18 and fixing when being fixed on blast device on the framework with Screw etc., perhaps adopt the mounting fixture 21 of the blast device shown in Fig. 7 A to 7C, owing to utilize the elasticity of hook 22 that blast device is pushed, but support housing peripheral part 10 and need not to adopt Screw normally carries out the fixation method of snap ring mode.

In the occasion of blast device with precision making completely, though do not produce the vibration of radial direction, but in fact in part that constitutes motor and fan, there is error respectively, so when motor turns round, bring out the cycle unbalance vibration consistent with rotating speed by these imbalances.

In the past or the occasion of the blast device of the foregoing description 1, motor part is the state that is directly delivered to framework through the vibration that spoke produces in motor part with directly being connected as the mounting hole of the assembly department of motor or with the housing peripheral part.

On the other hand, in embodiment 2, because spoke passes annular wall and for the fixing part indirect securement, motor part constitutes with respect to fixing part and is flexibly supported, because vibration exists the occasion of unbalance vibration to a certain degree also can decay and is delivered to fixing part at motor, situation minimizings such as resonance take place in the framework that blast device is installed, and the result is the noise and the vibration that can suppress as whole framework.

In addition, decay reliably for making vibration, the natural frequency that preferably makes this vibration system is compared further reduction with the motor speed as the basis of the excited frequency of motor.

Here, because it is very big that whole framework quality is compared with blast device, be replaced into the diagrammatic illustration figure of simple single vibration system of vibrating that the spring by as the spoke of the quality of the motor of oscillating body and fan and this oscillating body of yielding support and annular wall shown in Fig. 8 A constitutes so consider vibration with the radial direction (radially) of motor.

As represent total quality with m (kilogram) as the motor and the fan of oscillating body, with the spring constant between k (Newton/meter) expression hub portion and the assembly department (for the ratio of the counter-force of radial direction distortion), then the natural frequency F of this vibration system (hertz) represents with following formula:

N = 2 π \sqrt{\frac{k}{m}}

Fig. 8 B is applied to the frequency and the amplitude of external force and the explanatory drawing of the ratio of the amplitude of vibration of the external force on this vibration system for expression.

Shown in Fig. 8 B, the amplitude of vibration roughly changes with external force under the low occasion of external force frequency, but amplitude sharply increases near natural frequency F, then slowly diminishes after surpassing natural frequency, and the amplitude of vibration finally levels off to zero.

Therefore, can reduce vibration greater than natural frequency F by making rotational speed N (1/ second) as the motor of excitation force.Promptly satisfy following relation by being set at

N > 2 π \sqrt{\frac{k}{m}}

Because of the vibration attenuation of motor and be passed to framework,, realize low noise, low vibration so can suppress the vibration of framework.

And the bigger material of the damping force by selecting PBT (polybutylene-terephthalate), PP (polypropylene) material of etc.ing itself is as case material, when making motor start-up or the vibration attenuation of low speed when turning round, can further improve effectiveness in vibration suppression.

(embodiment 3)

Fig. 9 A to 9D represents the housing of embodiment 3 blast device.Wherein, Fig. 9 A is a profile, and Fig. 9 B is a front elevation, and Fig. 9 C is a sectional drawing, and Fig. 9 D is the X-X1 sectional drawing.

In Fig. 9 A to 9D, the difference of embodiment 3 housing and the foregoing description 1 is that week and air bag portion 11 are communicated with in the discharge side part annular wall of annular wall, form a plurality of grooves 19 that stretch out vertically, and other parts are then identical with embodiment 1.

This groove 19 can improve characteristic for blast device effectively in particular for the occasion at the high state of static pressure.

Figure 10 is the explanatory drawing of the air flows under the operation condition of the blast device of expression present embodiment 3.

As shown in figure 10, because comprising near the blade end eddy current of the turbulent eddy current that produces the blade front end blows out to air bag portion from groove 19, it on the rotating fan state of generation blade end eddy current within reason, the blade fore-end that hinders one's work because of this blade end eddy current also can fully be worked in the past, so air quantity increases.

In addition, because comprising the air stream of the turbulent eddy current 8 that blows out from groove 19 also emits by groove 19 rectifications and to air bag portion 11, and further emit in the space portion decay of air bag portion 11 and to the outside, so when reducing noise, because the air stream that blows out from groove 19 is transformed to static pressure effectively and the static pressure efficiency of fan is improved.

The figure of Figure 11 for the air volume-static pressure characteristic of this blast device is compared the characteristic of the blast device in the past of same size and embodiment 1 and embodiment 3 blast device.

By the curve (a) of Figure 11 as can be known, the air quantity characteristic that embodiment 1 blast device is compared when the pressure higher state with blast device in the past is more excellent, and the blast device of present embodiment 3 then keeps better air quantity characteristic.Its result is shown in the curve (b) of Figure 11, and the blast device of present embodiment 3 can improve static pressure efficiency significantly, and can improve the performance under the higher condition of pressure significantly.

On the other hand, under the lower condition of pressure, the blast device of present embodiment 3 then reduces state for air quantity conversely.Do not producing showy eddy current on the fan under the illustrated condition lower by pressure, the opposite air that produces is from groove 19 all flowing of flowing in annular wall 2, produce flowing of air circulation at the blade fore-end, air quantity descends, meanwhile, because because of the loss of air viscosity produce power, fans drive power increases at groove 19 places, the static pressure efficiency of fan worsens.

Therefore, the occasion of using under the lower state of static pressure realizes low noise by the embodiment 1 of the no groove 19 of use or embodiment 2 housing, and next by using the housing of present embodiment 3 at the higher state of static pressure, because the draft capacity of fan improves, so can obtain high cooling effectiveness.

In addition, when above-mentioned blast device load facility is used, because the draft capacity height can reduce rotation speed of the fan and use, thus have the effect of the power consumption that can reduce blast device or quietization etc., and have the effect of raising reliability.Perhaps under the situation that identical power consumption uses, can obtain the effect that draft capacity is good, cooling capacity improves.

In addition,, need not put speech though in the foregoing description 2 and embodiment 3, narrated the mould-forming method of housing, these housings also can with embodiment 1 identical only up and down the simple mould structure of core form.

Claims

1. blast device, be separated with interval and formation annular wall (2) and have integrally formed described annular wall (2) and the housing of the hub portion (16) of fixed motor (3) with the blade front end of fan (1), it is characterized in that, the terminal of described annular wall (2) is an interrupt status discharging side, is formed with the air bag portion (11) that has certain volume and open to the discharge side between annular wall periphery and housing outer peripheral portion.

2. blast device as claimed in claim 1 is characterized in that, described annular wall (2) is by making the local first area that enlarges of internal diameter and constitute with second area that the preceding splaying of blade dwindles, thereby makes and attract the gap of the blade front end of side to increase in fact.

3. blast device as claimed in claim 1 is characterized in that, the hub portion of described housing (16) combines with annular wall portion (2), is not directly installed in housing peripheral part (10) and the mounting hole portion (18).

4. blast device, it is characterized in that, as total quality, with the spring constant between k (Newton/meter) expression hub portion (16) and the assembly department with m (kilogram) expression motor (3) and fan (1), with the rotating speed of N (1/ second) expression motor, then housing is set for and is satisfied following relation:

N > 2 π \sqrt{\frac{k}{m}}

5. blast device, be separated with at interval and formation annular wall (2) with the blade front end of fan (1), and housing with hub portion (16) of integrally formed described annular wall (2) and fixed motor (3), it is characterized in that, above-mentioned annular wall (2) is by making the local first area that enlarges of internal diameter and constituting with second area that the preceding splaying of blade dwindles, thereby make and attract the gap of the blade front end of side to increase in fact, the terminal of second area is an interrupt status discharging side, have certain volume and when discharging the air bag portion (11) that side open being formed with between annular wall periphery and the housing outer peripheral portion (10), on described annular wall (2), be formed with all and the groove (19) that can make the air flows of air bag portion (11) annular wall in.

6. as each described blast device in the claim 1,4,5, it is characterized in that housing is with the die forming that only is made of core (12,13) up and down.